Should we introduce a sharper terminology? I think, a typical Greenbergian
`family' is quite different from the indoeuropean `family' or the germanic
`family' in time depth and the possibility of constructing a
proto-language.
Biologists have developped for a long time a whole set of notions, from
species and genus to families, classes and orders. It seems, that such
kind of differentiated terminology would do something good to historical
linguistics, too.
--J"org Knappen.

I was really surprised to read Jacques Guy's declaration
that n-ary comparison is just repeated binary comparison,
and not to read any objections from anybody else.
There are many important differences, which mostly
indicate that n-ary comparison is a much superior
strategy for doing comparative linguistics.
The bigger the n, the bigger the chance that we will
recover more of the proto-language (e.g., more of
the vocabulary).
The bigger the n, the less the chance that we will be
misled by a spurious set of correspondences.
In some situations, a smallish value for n may not
offer these advantages (so that in certain special
cirucmstances ternary comparison, say, may be worse
than binary), but in general n-ary is better.
Nor surprising then that in work on such families
as Indo-European, Uto-Aztecan, Afro-Asiatic, and so on,
no one to my knowledge has ever proceeded on binary
basis, comparing for example every pair of IE
languages.
Alexis MR